After a big of digging around on a server today, I followed my nose to where the log files are held.

qmail is started from within /etc/init.d/qmail. Searching for qmail-start reveals two ways in which qmail can be started, the Debian way or the “other” way. As this is CentOS we need the “other” way, which is:

qmail-start "$defauldelivery" splogger qmail &

The splogger argument tells qmail to use the syslog for logging, and CentOS uses rsyslog so look in the file /etc/rsyslog.conf. There you will find the line:

mail.*                    -/usr/local/psa/var/log/maillog

which finally leads us to the path to the qmail log file:

/usr/local/psa/var/log/maillog

Phew, got there at last! 🙂